@Water_kel

You could prove that they are not a scam by posting a hashed version of the Tips before the matches start and the plain text after.
The good thing about this is that no one would be able to get them for free, but they will be able to tell that the tips and hit % is real and has not been altered to hide losing tips.

It might seem like a lot of work but it really isn't, hashing the tips would only take a minute, google "sha-256 hash calculator" or go to http://www.xorbin.com/tools/sha256-hash-calculator  enter tip in plain text click "calculate" and you get a sha-256 version of the tip.
For example:
Text: Real Madrid -2.5
Hash: 54fb9c0176adf0f7070dc2d6a9bc4f61a7bf1d8140acab9bb40a60d60426cd77

Do these for 30 to 50 tips and everyone would be able to judge the real hit rate, before risking their bankrolls on inaccurate tips or money on potential scams.